The present invention relates to systems and methods for retaining walls that support vertical or inclined excavation cuts, embankments and the like. In particular, the present invention introduces an environmentally friendly, modular and inexpensive way of structurally supporting soil through helical piers driven into the ground, horizontal waler rods, vertical extensions and interlocking connectors. The resulting structure can withstand high structural loads, while creating a minimal environmental impact.
Retaining walls in civil engineering serve to prevent erosion or a collapse of excavation cuts and soil embankments. They must withstand significant structural loads, while minimizing the cost, the time to erect, and their environmental impact. The retained soil may be vertical or inclined, which poses different types of issues to be dealt with, an inclined wall being more prone to the erosion problems, while vertical walls are more prone to a collapse.
The need for retaining walls has been recognized in civil engineering for a long time. Many methods for building retaining walls have been developed. Traditionally, retaining walls have been made, for example, of a contiguous wire mesh, concrete or brick blocks with interlocking features, or by pouring concrete that is typically supported by structural steel beams. Some of these traditional methods have significant environmental impact, like, for instance, pouring concrete and/or driving the steel beams into the ground. This type of retaining wall can have an extremely high bearing capacity, but the cost and the environmental impact, both to erect and to remove, of such a wall are very significant. Some other retaining walls are made of interlocking brick or concrete elements. Such retaining walls are well-suited for the inclined soil slope, but are usually not useful for building vertical walls due to their inherently weak lateral load-bearing capacity.
Other retaining walls rely on boxes or wire mesh cages that are pre-filled with stone, brick or soil. These walls occupy significant lateral space in order to achieve the requisite load bearing for the vertical walls. Retaining walls are also built by first creating a strong L-shaped wire mesh surface. Next, the space between the wire mesh and the inclined soil surface is filled with soil or rock. The resulting structure tends to have significant load-bearing capacity, but is expensive, non-removable and environmentally degrading.
There are also retaining walls that use helical piers as a foundation element which is positioned in the soil. One such method creates an in-situ pile with soil displacer plates, which create a hollow cylindrical space in the tail of a helical pier rotated into the ground. Next, a column of concrete is built on top of this created foundation element. However, these methods are quite invasive due to the augered nature of the tie-back to the helical pier, and they result in essentially a non-removable retaining wall.
Thus, there exists a need for systems and methods for building the retaining walls with significant load-bearing capacity, modular structure, short assembly time, and minimal environmental impact.